Devices for measuring and displaying small changes in the resistance of a living body have previously been disclosed in U.S. Pat. Nos. 3,290,589 and 4,459,995 as well as U.S. Pat. No. 6,011,992. These devices generally include a resistance measuring circuit, an amplifier circuit and an indicator circuit. In operation, the device measures the small resistance changes utilizing the resistance measuring circuit to generate a measurement signal indicative of the magnitude of resistance. The measurement signal is then amplified by the amplifier circuit, and the amplified signal is used to drive a display such as an electromagnetically-responsive needle of a meter. The reliability of the readings has depended not only proper calibration of the device, but also on the accurate adjustment of circuit gains and sensitivities as the living body is monitored.
Devices of this type were first conceived and developed by inventor Hubbard for use in monitoring, or auditing, individuals as part of a counseling protocol. The devices are utilized to detect small changes in the electrical resistance of the audited person as that person looks at aspects of his own existence in order to improves his ability to confront what he is and where he is. The ability to detect and visually perceive the occurrences of very small, and sometimes quite fleeting, resistance changes as well as certain patterns of changes is essential to accurate and maximally effective auditing of the individual.
While the foregoing prior art devices have been suitable for detecting the resistance changes in the living body, they have been difficult to calibrate correctly and difficult to operate in a manner that consistently produces accurately perceived display readings. It appears that these difficulties arise from such characteristics as signal non-linearities, as well as age-related and temperature-related component changes that can mask or falsely report small but meaningful measurement changes.
Inventor Hubbard recognized that signal non-linearities were a significant factor that greatly complicated the reliable display of needed information, and that the interaction between range and sensitivity adjustments on such devices further complicated the ability to obtain clear readings. Mr. Hubbard further identified slight delays as small as 0.1 seconds in displaying resistance changes as a further source that complicated auditing and determined that the most effective display required even the smallest possible resistance changes to be perceived with as little delay as possible.